My best friend's daughter didn't come out talking until age 4. They said when she was around the age of saying first words she one day said "purple" and then stfu for a few years. It was like she totally knew how to do it, she didn't want to do it around ANYONE though..her mom would catch her playing in her room whispering with her toys but would clam up if she saw she had been found out. They were a little worried I guess, got a speech therapist and everything, but she didn't need it, she just started having conversations at 4...She's not almost 11 and a super genius.. like bumped up two grades smart.